Cisco Linksys WPC11-V31 Wireless Network PC Radio Card User Manual wpc11 ver3 0 user guide

Cisco-Linksys, LLC Wireless Network PC Radio Card wpc11 ver3 0 user guide

Contents

Users Manual 2

32Chapter 7: Configuration UtilityThe Configuration Utility is provided to allow you further customization ofthe Network PC Card and your wireless network.Once the Configuration Utility has been installed, an icon will be placed in thesystem tray (next to the clock) when the Network PC Card is inserted, as shownin Figure 7-1. You can also start the Configuration Utility by clicking the Start button, select-ing Programs, and choosing the folder for the Network PC Card. ChooseConfiguration Utility. You will see the Wireless LAN Configuration Utilityscreen (shown in Figure 7-1). This utility is divided into six parts: Link Info,Configuration, Site Survey, Encryption, Advanced, and About. You shouldchange all configuration settings for your Network PC Card using this utilityand not under the Network Properties section in your Control Panel.LINK INFOThe Link Info screen (shown in Figure 7-2) provides information about the cur-rent link between the Network PC Card and a wireless Access Point.When in Infrastructure Mode, State will display the connection statistics forthe network segment that you are on.The Current Channel field shows to what channel the Network PC Card is set.The Current Transfer Rate field shows the transfer rate in megabits per sec-ond.The Current Service Set Identifier shows the current SSID set for the wire-less network. This SSID can be modified at the Configuration screen.The Throughput fields show the rate at which data is transferred and receivedin Bytes per second.Using the Configuration UtilityFigure 7-1If this screen does not appear automatically, you can access the installation byclicking the Start button and choosing Run. In the drop-down box provided,type D:\setup.exe (where D: is the letter of your CD-ROM drive). Alternately,double-click My Computer, and then double-click the CD-ROM drive wherethe Setup Utility CD is located. Double-click the Setup.exe icon that appears.Follow the instructions that appear on your screen. If you have any questionsor difficulty, refer to the section called Installing the Drivers andConfiguration Utility for Windows 95, 98, ME, and 2000.Network PC Card Instant WirelessTMSeries31
34CONFIGURATIONThe Configuration screen, shown in Figure 7-3, allows you to customize thesettings for the Network PC Card and your wireless network.The Wireless Mode setting determines the architecture of your wireless net-work. Select Ad-Hoc or Infrastructure Mode depending on your networktype. The Ad-Hoc mode is used for a simple peer-to-peer network and allowsthe sharing of local resources only between Network PC Cards without need-ing a wireless Access Point. The Infrastructure mode allows a wireless net-work to be integrated into an existed, wired network through an Access Point.Infrastructure networks permit roaming between Access Points while main-taining a connection to all network resources.An acronym for Service Set Identifier, SSID is the unique name shared amongall points in a wireless network. The SSID must be identical for all points in thenetwork. It is case sensitive and must not exceed 32 characters.Figure 7-3The Link Quality field will display a bar indicating the percentage, between 0and 100 percent, of the quality of the link. The higher the percentage, the bet-ter the link. The Signal Strength field will display a bar indicating the percentage, between0 and 100 percent, of the strength of the signal. The higher the percentage, thestronger the signal.Note: When in Ad-Hoc mode, Link Quality andSignal Strength indicators will not be available.Figure 7-2Network PC Card Instant WirelessSeries33
35ENCRYPTIONOn the Encryption screen, shown in Figure 7-5, you can set the level of securitywith which you will be using the Network PC Card. Under the drop-down box, you can choose to have WEP encryption Disabled, 64-Bit, or 128-Bit. Wired Equivalent Privacy (WEP) is an encryption scheme used toprotect wireless data communication. The Disabled setting prevents the sharing ofdata with other computers on the WEP network. When selecting Manual Entryfor the WEP Key Entry, enter the hexadecimal number set by other wireless WEPsettings; these settings have to be identical to the WEP encryption on all points inyour wireless network in order to network to your Network PC Card.Note: In order to enable WEP encryption,hexadecimal values must be entered.Figure 7-5Note: The WEP Key Entry must match the Key on all other deviceson the wireless network, or else this device will be unable to trans-mit or receive data.The Transfer Rate field shows the current transfer rate for the Network PCCard. To optimize performance and range, the TX Rate should be set to FullyAutomatic, which will automatically adjust the transfer speed for best per-formance and longest range.The Channel setting specifies the channel used in wireless communication andshould be set to the same channel as the other points in the wireless network.This setting can only be adjusted in Ad-Hoc mode.Power Saving Mode, or PS Mode, enables or disables the power saving featuresof your Network PC Card. SITE SURVEYThe Site Survey screen shows the available access points and their features.Click on the desired access point. Then click Connect to connect or Search tosearch for more access points.Network PC Card Figure 7-4Instant WirelessTMSeries36
37The RTS Threshold Value should remain at its default setting of 2,432. A pre-amble is a signal used to synchronize the transmission timing between two ormore systems. A series of transmission pulses is sent before the data to indicatethat “someone is about transmit data.” This ensures that systems receiving theinformation correctly when the data transmission starts.Security is used for WEP only. By selecting Deny Unencrypted DataFrames, all unencrypted data will not be seen. For Authentication Type, youmay choose between Open System or Shared Key.Shared Key is when both the sender and recipient share a secret key. Bothunits use this key for an extended length of time, sometimes indefinitely.Any eavesdropper that discovers the key may decipher all packets until thekey is changed.Open System, the default setting, is when the sender and the recipient donot share a secret key. Each party generates its own key-pair and asks thereceiver to accept the (usually randomly) generated key. Once accepted,this key is used for a short time only; then a new key is generated andagreed upon.The Preamble Typeshould be set to Short (ifthe network environmentis “noisy”) or Long (if theenvironment is clear).Click OK to complete theconfiguration. ABOUTThe About screen (Figure7-7) shows the releaseinformation for the DriverVersion, ConfigurationUtility Version, andFirmware VersionFigure 7-7In order to enable 128-bit WEP encryption, choose 128 Bits in the drop-downbox. In the drop-down box near the bottom right-hand corner of the page,choose which Default Tx Key will be used for the encryption. By default, Key1 will be used. In the box corresponding to the default you chose, enter a hexa-decimal number that the encryption algorithm will be based on. Click ApplyChanges when you are done.ADVANCEDThe Advanced screen (Figure 7-6) allows you to set the FragmentationThreshold, the RTS/CTS Threshold, and the Preamble Type. TheFragmentation Threshold Value indicates how much of the network resourcesis devoted to recovering packet errors. The value should remain at its defaultsetting of 2,432. If you experience high packet error rates, you can decrease thisvalue but it will likely decrease overall network performance. Only minor mod-ifications of this value are recommended. Network PC Card Figure 7-6Instant WirelessSeries38
3. Highlight Protocol from thelist of network componenttypes, as shown in Figure 8-3,and click the Add button.4. From the screenshown in Figure 8-4, select Microsoftfrom the list of“Manufacturers”and TCP/IP fromthe list of “NetworkProtocols” and clickthe OK button.Repeat steps twothrough four toinstall other proto-cols, such asNetBEUI or IPX/SPX.5. To verify that the drivers areworking under EnhancedMode on the Driver Type tabor reconfigure the card onthe Advanced tab, go to thescreen shown in Figure 8-2and click the Properties but-ton. This will bring up theProperties Tabs, where suchvalues can be refined.When finished, you mustrestart your computer tocomplete installation.40Chapter 8: Installing NetworkProtocolsProtocols are necessary for computers to communicate on your network. 1. From the StartMenu, selectSettings andbring up theControl Panel,as shown inFigure 8-1. Fromthe ControlPanel, double-click theNetwork icon.2. Select Instant WirelessNetwork PC Card V3.0from the list (as shown inFigure 8-2) and click theAdd button.39Figure 8-3Figure 8-4Figure 8-5Network PC Card Figure 8-1Figure 8-2Instant WirelessSeries
2. Select AuthenticationAlgorithm from the listprovided and select aValue from the drop-down menu on theright, as shown inFigure 9-2. WECA Compliant (Default) (also referred to as Open Authentication) The sender and recipient do NOT share a secret key. Each party generates itsown key-pair and asks the receiver to accept the generated key. Once accept-ed, this key is used for a short time only. Must use Shared with WEP (Optional) This is when both the sender and recipient share a secret key. They use this keyfor an extended length of time. Any eavesdropper that discovers the key maydecipher all packets until the key is changed. As indicated, you should alwaysuse WECA Compliant (Always Use) unless you have some other reason to doso. Choose Channel to continue or click the OK button to finish setting theAdvanced OptionsFigure 9-2Network PC Card Chapter 9: Advanced PropertiesThe Advanced Properties of the card are supplied for fine tuning the card’s set-tings. These values should only be changed by those completely familiar withboth the operating system and the settings of the network. Unless your specif-ic situation requires changing them, the default settings should be sufficient foryour card’s proper operation. Linksys advises that you change these values inthe Configuration Utility rather than using this method, to insure that the set-tings you change will be recognized everywhere.Check your wireless network settings before changing any of these values. 1. To access the Network Configuration screen (shown in Figure 9-1), click theStart button, choose Settings and open the Control Panel. Double-click theNetwork icon and choose the Advanced tab.The Advanced Properties for Windows 95, 98, ME, and 2000Figure 9-1Instant WirelessTMSeries41 42
5. The FragmentationThreshold Value,shown in Figure 9-5 indi-cates the maximum sizeof the transmit frame.Any data frame largerthan this value will befragmented into multipleframes. Lowering thisvalue usually means alower frame error rate,but a lower value alsocreates more overhead,which negatively affectsnetwork performance.The value can only beentered in increments of128. Only minor modi-fications of this value arerecommended. ClickMaximum ListenInterval to continue orthe OK button to finishsetting the AdvancedOptions.6. The Maximum ListenInterval, as shown inFigure 9-6, only applieswhen operating in theInfrastructure modewhile Power Saving isenabled. The value youinput here will deter-mine how often the com-puter “wakes up” fromthe power saving modeto receive any packetsthat were sent while itwas “asleep.” The higherthe value entered here,the longer the time yourcomputer “sleeps”between waking up tocheck for packets. ClickNetwork Type to con-tinue or the OK buttonto finish setting theAdvanced Options.3. The Channel setting,shown in Figure 9-3,must be the same forall wireless points inthe network. Use thesettings, 1-11, to findthe best channel foryour connection. Forfurther information,see Chapter 7:ConfigurationUtility. Once yourcard is configured,click the OK button tofinish setting theAdvanced Options.4. Select either Disabled, 64bit, or 128 bit as thevalue under Encryption,shown in Figure 9-4.Wired EquivalentPrivacy (WEP) is anencryption method usedto protect wireless datacommunication. TheDisabled setting pre-vents the sharing of datawith other computers ona WEP network. For datasharing to be enabled,select either 64 or 128 bitencryption, dependingon your needs. For fur-ther information, seeChapter 7:Configuration Utility.Once your card is con-figured, click OK to fin-ish setting the AdvancedOptions.Network PC Card Figure 9-5Figure 9-6Figure 9-3Figure 9-4Instant WirelessTMSeries43 44
9. A preamble is a signalused to synchronizethe transmission tim-ing between two ormore points in yourwireless network.The default setting isLong Tx Preamble(as shown in Figure 9-9). Long Tx Preambleallows extra time forthe digital decoder toprocess the initialheader packets, but istransmitted at11Mbps. Short TxPreamble allows forless time to processthe packets, but initialpackets are transmit-ted at 2Mbps. ClickSSID to continue orthe OK button to fin-ish setting theAdvanced Options.10. RTS Thresholdshould remainDisabled the defaultsetting, as shown inFigure 9-10. Do notchange the setting ofthe RTS Thresholdunless connectionquality is poor. Then,increase this setting bya small value to estab-lish a better connec-tion. Click NetworkType to continue orthe OK button to fin-ish setting theAdvanced Options.Network PC Card 7. Select Network Type(Figure 9-7) and select aValue, from the dropdown menu, of eitherInfrastructure or Ad-Hoc. The Infrastructure modeallows a Network PCCard to communicatewith a wired networkemploying an accesspoint, while the Ad-Hocmode allows wireless-to-wireless, peer-to-peercommunication. ClickPower Save Mode tocontinue or the OK but-ton to finish setting theAdvanced Options.8. Select Power SaveMode (shown in Figure9-8) and select eitherEnabled or Disabledfor the Value. Disabledwill allow for uninter-rupted data communica-tion. Selecting Enabledallows your notebook toenter “sleep” mode andcould interrupt datacommunication. Forfurther informationabout Power SaveMode, see Chapter 7:Configuration Utility.Click Preamble Modeto continue or the OKbutton to finish settingthe Advanced Options.Figure 9-9Figure 9-10Figure 9-7Figure 9-8Instant WirelessTMSeries45 46
13. The WEP Passphrase (Figure 9-13) value allows the user to change thepassphrase that is used to generate the encryption key for WEP. Anyalphanumeric value can be entered here, but it will only be activated if youchoose either 64 or 128 bit under Encryption. This value can also bechanged using the Configuration Utility. For further information, seeChapter 7: Configuration Utility.Once your card is configured, click the OK button to finish setting theAdvanced Options.Network PC Card 11. The value for SSID(Figure 9-11) dependson what NetworkType was selected.Infrastructure net-works should have thesame SSID as theAccess Point. Allclients in an Ad-HocNetwork should sharethe same SSID. ClickTransmit Rate tocontinue or the OKbutton to finish set-ting the AdvancedOptions.12. The Transmit Rateaffects the speed oftransmission to anoth-er wireless device.The rate can either beset to a fixed value orleft at the default valueof Full Auto, as shownin Figure 9-12, whichlets the computerdetermine the besttransfer rate. The firstoption, Auto Select 1or 2, is for compatibil-ity with older wirelessequipment. ClickWEP Passphrase tocontinue or the OKbutton to finish settingthe Advanced Options.Figure 9-13Figure 9-11Figure 9-12Instant WirelessTMSeries47 48
2. The IRQ Base level(Figure 9-15) can bechanged in order toavoid possible conflictswith other systemdevices. The defaultsetting for the NetworkPC Card is 7. Thisvalue should only bechanged if the Carddoes not work properly.3. The Mode setting (Figure9-16) should be eitherInfrastructure or Ad-Hoc, depending uponyour network’s settings.The Infrastructuremode allows a Network PC Card tocommunicate with awired network employingan access point, while theAd-Hoc mode allowswireless-to-wireless, peer-to-peercommunication. Formore information aboutthese settings, refer to thesection in Chapter 3called Ad-Hoc versusInfrastructure Mode.The Advanced Properties screen allows you to make modifications to yourNetwork PC Card, optimizing performance. These properties are accessed byright-clicking on the Network Neighborhood icon on the desktop. SelectProperties from the menu that appears. From the tabbed window that appearsnext, click the Adapters tab. Highlight Instant Wireless Network PC CardV3.0 and then click the Properties button. The screen in Figure 9-14 shouldappear. Choosing improper settings in these fields can keep the WirelessNetwork PC Card from functioning properly. Follow these steps to configurethe Advanced Properties fields:1. The I/O Base setting,shown in Figure 9-14,should be unique andnot conflict with anyother device settings inyour system.The Advanced Properties for Windows NTNote: In order to check for potential IRQ conflicts,run WINMSD by selecting RUN from the Start menuand typing winmsd.exe and pressing the Enter key.Network PC Card Figure 9-14Figure 9-15Figure 9-16Instant WirelessSeries49 50
6. RTS Threshold shouldremain in the defaultsetting of Disabled, asshown in Figure 9-19.Do not change the set-ting of the RTSThreshold unless con-nection quality is poor.Then, increase this set-ting by a small value toestablish a better con-nection.7. FragmentationThreshold shouldremain in the defaultsetting of Disabled,as shown in Figure 9-20. Do not change thesetting of theFragmentationThreshold unless con-nection quality ispoor. Then, increasethis setting by a smallvalue to establish abetter connection.4. The SSID (as shown inFigure 9-17) dependson what Mode isselected. If the Modeis Infrastructure, itshould have the sameSSID name as theAccess Point. If theMode is Ad-Hoc, allclients should sharethe same SSID name.5. The DS Channel set-ting (Figure 9-18) mustbe the same for allwireless points in thenetwork. Use the set-tings, 1-11, to find thebest channel for yourconnection.Network PC Card Figure 9-17Figure 9-18Figure 9-19Figure 9-20Instant WirelessTMSeries51 52
10. The Authenticationsetting, shown in Figure9-23, is Open Systemby default. OpenSystem is another namefor WECA compliant.WECA Compliant (Default) (also referred to as Open Authentication) The sender and recipient do NOT share a secret key. Each party generatesits own key-pair and asks the receiver to accept the generated key. Onceaccepted, this key is used for a short time only; thereafter a new key is gen-erated and agreed upon.Shared Key (Optional) This is when both the sender and recipient share the same key. They use thiskey for an extended length of time. Any eavesdropper that discovers the keymay decipher all packets until the key is changed. As indicated, you shouldalways use WECA Compliant (Always Use) unless you have some other rea-son to do so.Choose Listen Interval to continue or the OK button to finish setting theAdvanced Options8. Under Power Savingmode (Figure 9-21),select either Enabledor Disabled. Disabledwill allow for uninter-rupted data communi-cation. SelectingEnabled allows yournotebook to enter“sleep” mode andcould interrupt datacommunication. Forfurther informationabout Power SaveMode, see Chapter 7:Configuration Utility.9. Select either Disabled,64 bit, or 128 bit asthe value underEncryption, as shownin Figure 9-22). WiredEquivalent Privacy(WEP) is an encryp-tion scheme used toprotect wireless datacommunication. TheDisabled setting pre-vents the sharing ofdata with other com-puters on a WEP net-work. For data sharingto be enabled, selecteither 64 or 128 bitencryption. Network PC Card Figure 9-21Figure 9-22Figure 9-23Instant WirelessTMSeries53 54
56Chapter 10: TroubleshootingThis chapter provides solutions to problems usually occurring during the instal-lation and operation of the Network PC Card. Read the description below tosolve your problems. If you can’t find an answer here, check the Linksys web-site at www.linksys.com.1.My computer does not recognize the Network PC Card.Make sure that the Network PC Card is properly inserted into the PCMCIAslot. Note that the card can be inserted either way, but only correctly when itis inserted so that the “Instant Wireless” logo on the front of the card may notbe seen. If in doubt, try inserting the card both ways. The card will slide infurther when it is correct. 2.The Network PC Card does not work properly.•Reinsert the Network PC Card into your notebook’s PCMCIA slot. A beepshould be heard if the card is properly inserted.•For non-Windows environments, make sure that a PCMCIA card servicedriver is installed on your PC.•Open the Control Panel and click on the PC Card. Check whether it has aPCMCIA card in one of the sockets or not. If you find the Network PC Cardin one of the sockets, it means the card has been detected properly. If you seea yellow question mark, the resources are conflicting.•Right-click on My Computer and select Properties. Select the device man-ager and click the Network Adapter. You will find the Network PC Card ifit is installed successfully. If you see the yellow exclamation mark, theresources are conflicting. Click PCMCIA card and then click PCMCIAcard service. You will see the status of the Network PC Card. If there is ayellow question mark, please check the following:•Make sure your notebook has a free IRQ.•Make sure you have inserted the right card and installed the properdriver.Common Problems and SolutionsNetwork PC Card 11. The Listen Intervalsetting, as shown inFigure 9-24, shouldremain at 1 Beacon perSecond. Setting thishigher could result inslower data transfer.12. The TX Rate setting, asshown in Figure 9-25,should remain FullyAuto as set by default.Changing this to a dif-ferent transfer rate willlock in that rate andmay result in droppedconnections. Click the OK button tocomplete setting theseoptions.Figure 9-24Figure 9-25Instant WirelessTMSeries55
What is Infrastructure?An integrated wireless and wired LAN is called an Infrastructure configura-tion. Infrastructure is applicable to enterprise scale for wireless access to a cen-tral database, or wireless application for mobile workers.What is Roaming?Roaming is the ability of a portable computer user to communicate continu-ously while moving freely throughout an area greater than that covered by a sin-gle Wireless Network Access Point.To achieve true seamless connectivity, the wireless LAN must incorporate anumber of different functions. Each node and Wireless Network Access Point,for example, must always acknowledge receipt of each message. Each nodemust maintain contact with the wireless network even when not actually trans-mitting data. Achieving these functions simultaneously requires a dynamic RFnetworking technology that links Wireless Network Access Points and nodes.In such a system, the user’s end node undertakes a search for the best possibleaccess to the system. First, it evaluates such factors as signal strength and qual-ity, as well as the message load currently being carried by each WirelessNetwork Access Point and the distance of each Wireless Network Access Pointto the wired backbone. Based on that information, the node next selects theright Wireless Network Access Point and registers its address. Communicationsbetween end node and host computer can then be transmitted up and down thebackbone.As the user moves on, the end node’s RF transmitter regularly checks the sys-tem to determine whether it is in touch with the original Wireless NetworkAccess Point or whether it should seek a new one. When a node no longerreceives acknowledgment from its original Wireless Network Access Point, itundertakes a new search. Upon finding a new Wireless Network Access Point,it then re-registers, and the communication process continues.What is BSS ID?A specific Ad-hoc LAN is called a Basic Service Set (BSS). Computers in aBSS must be configured with the same BSS ID.What is ESSID?An Infrastructure configuration could also support roaming capability formobile workers. More than one BSS can be configured as an Extended ServiceSet (ESS). Users within an ESS could roam freely between BSSs while main-taining a continuous connection to the wireless network stations and WirelessNetwork Access Points.58If the Network PC Card does not function after attempting the above steps,remove the card and do the following:•Uninstall the driver software from your PC.•Restart your PC and repeat the hardware and software installation asspecified in this User Guide.3.I cannot communicate with the other computers linked via Ethernet inthe Infrastructure configuration.•Make sure that the notebook PC to which the Network PC Card is associat-ed is powered on.•Make sure that your Network PC Card is configured on the same channel andwith the same security options as the other computers in the Infrastructureconfiguration.Can I run an application from a remote computer over the wireless net-work?This will depend on whether or not the application is designed to be used overa network. Consult the application’s documentation to determine if it supportsoperation over a network.Can I play multiplayer games with other users of the wireless network?Yes, as long as the game supports multiple players over a LAN (local area net-work). Refer to the game’s documentation for more information.What is the IEEE 802.11b standard?The IEEE 802.11b Wireless LAN standards subcommittee formulatings stan-dards for the industry. The objective is to enable wireless LAN hardware fromdifferent manufacturers to communicate. What IEEE 802.11 features are supported?The product supports the following IEEE 802.11 functions: •CSMA/CA plus Acknowledge protocol •Multi-Channel Roaming •Automatic Rate Selection •RTS/CTS feature •Fragmentation •Power Management What is Ad-hoc?An Ad-hoc wireless LAN is a group of computers, each with a Network PCCard, connected as an independent wireless LAN. An Ad-hoc wireless LAN isapplicable at a departmental scale for a branch or SOHO operation.57Network PC Card Frequently Asked QuestionsInstant WirelessTMSeries
60What is ISM band?The FCC and their counterparts outside of the U.S. have set aside bandwidthfor unlicensed use in the ISM (Industrial, Scientific and Medical) band.Spectrum in the vicinity of 2.4 GHz, in particular, is being made availableworldwide. This presents a truly revolutionary opportunity to place convenienthigh speed wireless capabilities in the hands of users around the globe. What is Spread Spectrum?Spread Spectrum technology is a wideband radio frequency technique devel-oped by the military for use in reliable, secure, mission-critical communica-tions systems. It is designed to trade off bandwidth efficiency for reliability,integrity, and security. In other words, more bandwidth is consumed than in thecase of narrowband transmission, but the trade-off produces a signal that is, ineffect, louder and thus easier to detect, provided that the receiver knows theparameters of the spread-spectrum signal being broadcast. If a receiver is nottuned to the right frequency, a spread-spectrum signal looks like backgroundnoise. There are two main alternatives, Direct Sequence Spread Spectrum(DSSS) and Frequency Hopping Spread Spectrum (FHSS).What is DSSS? What is FHSS? And what are their differences?Frequency Hopping Spread Spectrum (FHSS) uses a narrowband carrier thatchanges frequency in a pattern that is known to both transmitter and receiver.Properly synchronized, the net effect is to maintain a single logical channel. Toan unintended receiver, FHSS appears to be short-duration impulse noise.Direct Sequence Spread Spectrum (DSSS) generates a redundant bit pattern foreach bit to be transmitted. This bit pattern is called a chip (or chipping code).The longer the chip, the greater the probability that the original data can berecovered. Even if one or more bits in the chip are damaged during transmis-sion, statistical techniques embedded in the radio can recover the original datawithout the need for retransmission. To an unintended receiver, DSSS appearsas low power wideband noise and is rejected (ignored) by most narrowbandreceivers. Would the information be intercepted while transmitting on air?WLAN features two-fold protection in security. On the hardware side, as withDirect Sequence Spread Spectrum technology, it has the inherent security fea-ture of scrambling. On the software side, the WLAN series offers the encryp-tion function (WEP) to enhance security and access control. Users can set it updepending upon their needs.59Can Instant WirelessTM products support file and printer sharing?Instant WirelessTM products perform the same function as LAN products.Therefore, Instant WirelessTM products can work with Netware, WindowsNT/2000, or other LAN operating systems to support printer or file sharing.What is WEP?WEP is Wired Equivalent Privacy, a data privacy mechanism based on a 40 bitshared key algorithm, as described in the IEEE 802.11 standard. Network PC Card Instant WirelessTMSeries
61devices access the line at exactly the same time, their signals collide. When thecollision is detected, they both back off and each wait a random amount of timebefore retrying. Database - A database is a collection of data that is organized so that its contentscan easily be accessed, managed, and updated. Default Gateway - The routing device used to forward all traffic that is notaddressed to a station within the local subnet.DHCP (Dynamic Host Configuration Protocol) - A protocol that lets networkadministrators manage centrally and automate the assignment of InternetProtocol (IP) addresses in an organization's network. Using the Internet's set ofprotocol (TCP/IP), each machine that can connect to the Internet needs a uniqueIP address. When an organization sets up its computer users with a connection tothe Internet, an IP address must be assigned to each machine. Without DHCP, theIP address must be entered manually at each computer and, if computers move toanother location in another part of the network, a new IP address must be entered.DHCP lets a network administrator supervise and distribute IP addresses from acentral point and automatically sends a new IP address when a computer isplugged into a different place in the network. DHCP uses the concept of a "lease" or amount of time that a given IP addresswill be valid for a computer. The lease time can vary depending on how long auser is likely to require the Internet connection at a particular location. It's espe-cially useful in education and other environments where users change frequently.Using very short leases, DHCP can dynamically reconfigure networks in whichthere are more computers than there are available IP addresses. DHCP supports static addresses for computers containing Web servers that needa permanent IP address. Domain - A subnetwork comprised of a group of clients and servers under thecontrol of one security database. Dividing LANs into domains improves per-formance and security.Driver - A workstation or server software module that provides an interfacebetween a network interface card and the upper-layer protocol software runningin the computer; it is designed for a specific NIC, and is installed during the ini-tial installation of a network-compatible client or server operating system.Network PC Card Chapter 11: GlossaryAd-hoc Network - An ad-hoc network is a wireless network or other small net-work in which some of the network devices are part of the network only for theduration of a communications session while in some close proximity to the restof the network.Architecture - The total design and implementation of the network. It includesthe network's topology, transmission technologies and communications proto-cols, management and security systems, and any other attributes that give a net-work a particular set of capabilities and functionalities.Backbone - The part of a network that connects most of the systems and net-works together and handles the most data.Bandwidth - The transmission capacity of a given facility, in terms of how muchdata the facility can transmit in a fixed amount of time; expressed in bits per sec-ond (bps).Bit - A binary digit. The value - 0 or 1-used in the binary numbering system.Also, the smallest form of data.BSS (Basic Service Set) - A group of Instant Wireless Network PC Card usersand an Access Point.Buffer - A buffer is a shared or assigned memory area used by hardware devicesor program processes that operate at different speeds or with different sets of pri-orities. The buffer allows each device or process to operate without being held upby the other. In order for a buffer to be effective, the size of the buffer and thealgorithms for moving data into and out of the buffer need to be considered bythe buffer designer. Like a cache, a buffer is a "midpoint holding place" but existsnot so much to accelerate the speed of an activity as to support the coordinationof separate activities. CSMA/CD (Carrier Sense Multiple Access/Collision Detection) - The LANaccess method used in Ethernet. When a device wants to gain access to the net-work, it checks to see if the network is quiet (senses the carrier). If it is not, itwaits a random amount of time before retrying. If the network is quiet and twoInstant WirelessTMSeries62
63Hop - The link between two network nodes.IEEE (The Institute of Electrical and Electronics Engineers) - The IEEEdescribes itself as "the world's largest technical professional society, promotingthe development and application of electrotechnology and allied sciences for thebenefit of humanity, the advancement of the profession, and the well-being of ourmembers." The IEEE fosters the development of standards that often become national andinternational standards. The organization publishes a number of journals, hasmany local chapters, and several large societies in special areas, such as the IEEEComputer Society.Infrastructure - An infrastructure network is a wireless network or other smallnetwork in which the wireless network devices are made a part of the networkthrough the Access Point which connects them to the rest of the network.IP Address - In the most widely installed level of the Internet Protocol (InternetProtocol) today, an IP address is a 32-binary digit number that identifies eachsender or receiver of information that is sent in packet across the Internet. Whenyou request an HTML page or send e-mail, the Internet Protocol part of TCP/IPincludes your IP address in the message (actually, in each of the packets if morethan one is required) and sends it to the IP address that is obtained by looking upthe domain name in the Uniform Resource Locator you requested or in the e-mailaddress you're sending a note to. At the other end, the recipient can see the IPaddress of the Web page requestor or the e-mail sender and can respond by send-ing another message using the IP address it received. IPX (Internetwork Packet EXchange) - A NetWare communications protocolused to route messages from one node to another. IPX packets include networkaddresses and can be routed from one network to another.IRQ (Interrupt ReQuest) - A hardware interrupt on a PC. There are 16 IRQ linesused to signal the CPU that a peripheral event has started or terminated. In mostcases, two devices cannot use the same line. ISM band - The FCC and their counterparts outside of the U.S. have set asidebandwidth for unlicensed use in the ISM (Industrial, Scientific and Medical)band. Spectrum in the vicinity of 2.4 GHz, in particular, is being made availableworldwide. This presents a truly revolutionary opportunity to place convenienthigh-speed wireless capabilities in the hands of users around the globe.Network PC Card DSSS (Direct-Sequence Spread-Spectrum) - DSSS generates a redundant bit pat-tern for each bit to be transmitted. This bit pattern is called a chip (or chippingcode). The longer the chip, the greater the probability that the original data canbe recovered. Even if one or more bits in the chip are damaged during transmis-sion, statistical techniques embedded in the radio can recover the original datawithout -the need for retransmission. To an unintended receiver, DSSS appears aslow power wideband noise and is rejected (ignored) by most narrowbandreceivers. Encryption - A security method that applies a specific algorithm to data in orderto alter the data's appearance and prevent other devices from reading the infor-mation. ESS - More than one BSS in a network.Ethernet - IEEE standard network protocol that specifies how data is placed onand retrieved from a common transmission medium. Has a transfer rate of 10Mbps. Forms the underlying transport vehicle used by several upper-level proto-cols, including TCP/IP and XNS.FHSS (Frequency Hopping Spread Spectrum) - FHSS continuously changes thecenter frequency of a conventional carrier several times per second according toa pseudo-random set of channels, while chirp spread spectrum changes the car-rier frequency. Because a fixed frequency is not used, illegal monitoring of spreadspectrum signals is extremely difficult, if not downright impossible depending onthe particular method.Firmware - Programming that is inserted into programmable read-only memory(programmable read-only memory), thus becoming a permanent part of a com-puting device. Fragmentation - Breaking a packet into smaller units when transmitting over anetwork medium that cannot support the original size of the packet. Gateway - A device that interconnects networks with different, incompatiblecommunications protocols. Hardware - Hardware is the physical aspect of computers, telecommunications,and other information technology devices. The term arose as a way to distinguishthe "box" and the electronic circuitry and components of a computer from theprogram you put in it to make it do things. The program came to be known as thesoftware.64Instant WirelessSeries
Packet - A unit of data routed between an origin and a destination in a network.Passphrase - Used much like a password, a passphrase simplifies the WEPencryption process by automatically generating the WEP encryption keys forLinksys products.PC Card - A credit-card sized removable module that contains memory, I/O, ora hard disk. PCMCIA - The PCMCIA (Personal Computer Memory Card InternationalAssociation) is an industry group organized in 1989 to promote standards for acredit card-size memory or I/O device that would fit into a personal computer,usually a notebook or laptop computer. Plug-and-Play - The ability of a computer system to configure expansion boardsand other devices automatically without requiring the user to turn off the systemduring installation.Roaming - The ability to use a wireless device and be able to move from oneaccess point's range to another without losing the connection.RTS (Request To Send) - An RS-232 signal sent from the transmitting station tothe receiving station requesting permission to transmit. Server - Any computer whose function in a network is to provide user access tofiles, printing, communications, and other services. Software - Instructions for the computer. A series of instructions that performs aparticular task is called a "program." The two major categories of software are"system software" and "application software." System software is made up ofcontrol programs such as the operating system and database management system(DBMS). Application software is any program that processes data for the user.A common misconception is that software is data. It is not. Software tells thehardware how to process the data.Spread Spectrum - Spread Spectrum technology is a wideband radio frequencytechnique developed by the military for use in reliable, secure, mission-criticalcommunications systems. It is designed to trade off bandwidth efficiency for reli-ability, integrity, and security. In other words, more bandwidth is consumed thanin the case of narrowband transmission, but the trade off produces a signal thatis, in effect, louder and thus easier to detect, provided that the receiver knows the66Network PC Card LAN - A local area network (LAN) is a group of computers and associateddevices that share a common communications line and typically share theresources of a single processor or server within a small geographic area (forexample, within an office building). Mbps (MegaBits Per Second) - One million bits per second; unit of measure-ment for data transmission.NetBEUI (NetBIOS Extended User Interface) - The transport layer for NetBIOS.NetBIOS and NetBEUI were originally part of a single protocol suite that waslater separated. NetBIOS sessions can be transported over NetBEUI, TCP/IP andSPX/IPX protocols. NetBIOS - The native networking protocol in DOS and Windows networks.Although originally combined with its transport layer protocol (NetBEUI),NetBIOS today provides a programming interface for applications at the sessionlayer (layer 5). NetBIOS can ride over NetBEUI, its native transport, which is notroutable, or over TCP/IP and IPX/SPX, which are routable protocols.NetBIOS computers are identified by a unique 15-character name, and Windowsmachines (NetBIOS machines) periodically broadcast their names over the net-work so that Network Neighborhood can catalog them. For TCP/IP networks,NetBIOS names are turned into IP addresses via manual configuration in anLMHOSTS file or a WINS server.There are two NetBIOS modes. The Datagram mode is the fastest mode, but doesnot guarantee delivery. It uses a self-contained packet with send and receivename, usually limited to 512 bytes. If the recipient device is not listening for mes-sages, the datagram is lost. The Session mode establishes a connection until bro-ken. It guarantees delivery of messages up to 64KB long. Network - A system that transmits any combination of voice, video and/or databetween users. Node - A network junction or connection point, typically a computer or work sta-tion.Notebook (PC) - A notebook computer is a battery-powered personal computergenerally smaller than a briefcase that can easily be transported and convenient-ly used in temporary spaces such as on airplanes, in libraries, temporary offices,and at meetings. A notebook computer, sometimes called a laptop computer, typ-ically weighs less than five pounds and is three inches or less in thickness. Instant WirelessTMSeries65
Chapter 12: SpecificationsStandards: IEEE 802.11b Channels: 11 Channels (US, Canada)13 Channels (Europe)14 Channels (Japan)Operating Range:Indoors: Up to 30M (100 ft.) @ 11 MbpsUp to 50M (165 ft.) @ 5.5 MbpsUp to 70M (230 ft.) @ 2 Mbps Up to 91M (300 ft.) @ 1 MbpsOutdoors: Up to 152M (500 ft.) @ 11 MbpsUp to 270M (885 ft.) @ 5.5 MbpsUp to 396M (1300 ft.) @ 2 MbpsUp to 457M (1500 ft.) @ 1 MbpsData Rate (Mbps): Up to 11Mbps (with automatic scale back)LEDs: Link, PowerDimensions: 4.5"x 2"x 0.3"(115mm x 54mm x 8mm)Unit Weight: 1.65 oz. (47g)Power: 3.3V or 5V DC, 275mA Tx, 225mA Rx, 200mA StandbyCertifications: FCC Class B, CE Mark Commercial Operating Temp.: 32ºF to 131ºF (0ºC to 55ºC)Storage Temp.: -4ºF to 158ºF (-20ºC to 70ºC)Operating Humidity: 0% to 90% Non-CondensingStorage Humidity: 0% to 95% Non-Condensing68Environmental parameters of the spread-spectrum signal being broadcast. If a receiver is nottuned to the right frequency, a spread-spectrum signal looks like backgroundnoise. There are two main alternatives, Direct Sequence Spread Spectrum(DSSS) and Frequency Hopping Spread Spectrum (FHSS).Static IP Address - A permanent IP address that is assigned to a node in an IPor a TCP/IP network. TCP (Transmission Control Protocol) - A method (protocol) used along with theInternet Protocol (Internet Protocol) to send data in the form of message unitsbetween computers over the Internet. While IP takes care of handling the actualdelivery of the data, TCP takes care of keeping track of the individual units ofdata (called packet) that a message is divided into for efficient routing throughthe Internet. TCP/IP (Transmission Control Protocol/Internet Protocol) - The basic commu-nication language or protocol of the Internet. It can also be used as a communi-cations protocol in a private network (either an intranet or an extranet). When youare set up with direct access to the Internet, your computer is provided with acopy of the TCP/IP program just as every other computer that you may send mes-sages to or get information from also has a copy of TCP/IP.Throughput - The amount of data moved successfully from one place to anoth-er in a given time period.Topology - A network's topology is a logical characterization of how the deviceson the network are connected and the distances between them. The most commonnetwork devices include hubs, switches, routers, and gateways. Most large net-works contain several levels of interconnection, the most important of whichinclude edge connections, backbone connections, and wide-area connections.TX Rate - Transmission Rate.WEP (Wired Equivalent Privacy) - A data privacy mechanism based on a 64-bitor 128-bit shared key algorithm, as described in the IEEE 802.11 standard. Workgroup - Two or more individuals that share files and databases. 67Instant WirelessSeriesNetwork PC Card
Chatper 14: Contact InformationFor help with the installation or operation of this product, contact LinksysTechnical Support at one of the phone numbers or Internet addresses below.Sales Information 800-546-5797 (LINKSYS)Technical Support 866-242-8558RMA Issues 949-261-1288Fax 949-261-8868Email support@linksys.comWeb http://www.linksys.comFTP Site ftp.linksys.com70Network PC Card 69Chapter 13: Warranty InformationBE SURE TO HAVE YOUR PROOF OF PURCHASE AND A BARCODEFROM THE PRODUCT’S PACKAGING ON HAND WHEN CALLING.RETURN REQUESTS CANNOT BE PROCESSED WITHOUT PROOF OFPURCHASE. IN NO EVENT SHALL LINKSYS’S LIABILITY EXCEED THE PRICEPAID FOR THE PRODUCT FROM DIRECT, INDIRECT, SPECIAL, INCI-DENTAL, OR CONSEQUENTIAL DAMAGES RESULTING FROM THEUSE OF THE PRODUCT, ITS ACCOMPANYING SOFTWARE, OR ITSDOCUMENTATION. LINKSYS DOES NOT OFFER REFUNDS FOR ANYPRODUCT. LINKSYS OFFERS CROSS SHIPMENTS, A FASTER PROCESS FOR PRO-CESSING AND RECEIVING YOUR REPLACEMENT. LINKSYS PAYSFOR UPS GROUND ONLY. ALL CUSTOMERS LOCATED OUTSIDE OFTHE UNITED STATES OF AMERICA AND CANADA SHALL BE HELDRESPONSIBLE FOR SHIPPING AND HANDLING CHARGES. PLEASECALL LINKSYS FOR MORE DETAILS.Instant WirelessSeries
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